+ static SGPropertyNode *adf_freq
+ = fgGetNode("/instrumentation/adf/frequencies/selected-khz", true);
+ static SGPropertyNode *nav1_freq
+ = fgGetNode("/instrumentation/nav/frequencies/selected-mhz", true);
+ static SGPropertyNode *nav1_sel_radial
+ = fgGetNode("/instrumentation/nav/radials/selected-deg", true);
+ static SGPropertyNode *nav2_freq
+ = fgGetNode("/instrumentation/nav[1]/frequencies/selected-mhz", true);
+ static SGPropertyNode *nav2_sel_radial
+ = fgGetNode("/instrumentation/nav[1]/radials/selected-deg", true);
+